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DAQ Knowledge Hardware News
February 4, 2025

Data acquisition on the test bench and in the vehicle

In the dynamic world of the automotive industry, the precise acquisition and analysis of measurement data is key. Whether it’s designing new vehicle models, optimizing individual components on the test bench, or conducting vehicle dynamics tests on the road, data acquisition plays a central role in every step of the development and optimization process.

In this blog post, we will take a closer look at data acquisition on the test bench and in the vehicle. We will describe the most important measurement variables, discuss common data acquisition requirements, and explain why DEWETRON measurement systems are the ideal solution for these applications.

 

What is measurement data acquisition on the test bench and in the vehicle?

Measurement data acquisition in the automotive industry covers countless areas on the test bench and for in-vehicle measurements. The most common and important measurement applications and analyses include:

  • Power analysis of combustion engines: based on speed and torque measurements,
  • Power analysis of electric motors: based on current and voltage measurements, as well as supplementary speed and torque analyses.
  • NVH (Noise Vibration Harshness) measurements: focusing on vibration and noise measurements,
  • Temperature measurements,
  • Vehicle dynamics tests: to assess the driving and handling capabilities of a vehicle,
  • Durability tests: using durability tests and analyzing road load data for individual components and entire systems,
  • ADAS (Advanced Driver Assistance System) tests: which require, among other things, precise position and speed determination.

As the focus on electromobility increases, the precise recording of electrical parameters is becoming particularly important. This includes measurements for testing and optimizing individual components such as the inverter, battery, or on-board charger, entire systems such as the drive system of an electric vehicle, and the vehicle range.

The majority of these measurements can be performed both on the test bench and during test drives on the road. Nowadays, even driving dynamics and durability tests are frequently conducted on test benches. For this purpose, realistic road conditions are simulated on the test bench. Nevertheless, real test drives are essential, as a perfect simulation of real conditions is not possible in practice. Conversely, most test bench measurements can also be taken during test drives in the vehicle. However, this requires specially-designed, yet handy measuring systems. In addition, measurements on the road are often limited due to the lack of space and are therefore not as extensive as on the test bench.

 

Which measurement variables are important?

Numerous measured variables are important for the previously mentioned tests and analyses on the test bench and in the vehicle. These naturally include the electrical variables such as current and voltage, which form the basis for calculating the electrical power. However, mechanical variables like torque and speed are also important, as they are needed to analyze mechanical performance.

In addition, acceleration measurements are of great relevance, especially in the form of vibrations and oscillations. For example, these are used for order analysis or modal analysis. Temperature and acoustic parameters also play an important role. They make it possible to determine the thermal behavior of components and to carry out noise and vibration analyses for NVH tests. In combination, these variables enable a comprehensive analysis of individual components as well as the entire vehicle behavior.

 

What are the requirements for the measurement devices and what needs to be considered during measurements?

Although the measured variables do not change, the requirements for the measuring systems differ between applications on the test bench and in the vehicle.

Major requirements for in-vehicle measurements
  • Compactness: Measuring devices for in-vehicle measurements must be small and space-saving. On the one hand, because there is only limited space in the vehicle. On the other hand, it should be possible to place the device close to the components to be measured. This is necessary, for example, to avoid high-voltage cables running through the entire vehicle.
  • Power supply: In order not to stress the vehicle’s electrical system, measuring devices should either have a low power consumption or an independent power supply. Ideally, the measuring devices should have their own battery for measurements in the vehicle.
  • Interfaces: The measuring device should have various interfaces in order to be able to communicate seamlessly with other vehicle sensors and control units. In particular, reading out OBD (on-board diagnostics) data during road tests is of great relevance.
  • Accuracy: The most important requirement, however, is accuracy. The more accurate a measuring device is, the better performance analyses, efficiency determinations, range, etc. can be determined.

Fig. 1: DEWETRON NEX[DAQ] in a car

Major requirements for test bench measurements
  • Versatility: For comprehensive analysis and evaluation, measuring devices on the test bench must be able to record a large number of measured variables simultaneously.
  • High sampling rates: There are countless dynamic and high-speed processes on test benches. To record these accurately and precisely, high sampling rates in the range of 10-20 million Hz are required. This is particularly important when measuring electrical signals or fast mechanical processes such as vibrations.
  • Data transmission and storage capacity: Due to the enormous amounts of data generated on the test bench, fast data transmission and sufficient storage capacity with fast data storage are required. Measurements on e-machine test benches, for example, can generate data volumes of 1 GByte per second.
  • Interfaces: The measuring devices must be able to communicate effectively with the test bench in order to transfer data and control the test process. Various interfaces such as Ethernet, CAN bus, EtherCAT, or XCP can be used for this purpose, with the choice depending on the specific requirements and capabilities of the test bench.
  • High accuracy: Accuracy is also a top priority here. Measuring devices on the test bench must be highly precise to provide accurate and reliable measurement data. This is particularly important for performance testing of vehicle engines and components.

Fig. 2: DEWETRON DEWE3-PA8 in a test bench

 

DEWETRON’s measurement technology for the automotive industry

DEWETRON serves the entire automotive industry with innovative measurement technology solutions. Our modular systems are versatile and applicable to various applications. A DEWETRON measurement system consists of three main components: the chassis, the measurement modules, and the measurement software. For each of these components, we offer a variety of options that are optimized for a wide range of applications.

Our chassis come in various designs, including classic rack-mount housings for stationary applications, modular housings with an integrated display, and front-end solutions for mobile measurements. Depending on the requirements, the chassis can be equipped with the appropriate signal conditioning modules. These modules cover a wide range of measurements, including vibration, strain, force, temperature, current, and voltage measurements. All our measurement modules are easily interchangeable and can be configured as required. We offer our powerful OXYGEN measurement software to visualize and analyze the measurement data. In addition to the basic version, OXYGEN offers numerous extensions for specific applications such as modal analysis, advanced power analysis, and much more. Thanks to this modular and flexible design, we offer optimal solutions for development test benches, road tests, and end-of-line test benches.

Fig. 3: Create your ideal DAQ system